Electric lamp or similar device



May 3, 1938.. P. o. CARTUN ELECTRIC LAMP OR SIMILAR DEVICE Filed March 2, 1957 2 Sheets-Sheet l [nventor Paul O. Carcun, b8 5,

H is Attorney.

May 3,- 1938. P. o. CARTUN ELECTRIC LAMP OR SIMILAR DEVICE Filed March 2, 19 2 Sheets-Sheet 2 Inventor Paul O. Car-tun,

b 7V 5. a y

His Attorneg Patented May 3,1938

UNITED STATES PATENT OFFICE Paul 0. Cartun, Cleveland Heights, Ohio, asaignor to General Electric Company, a corporation of New York Application March 2, 1937, Serial No. 128,617

8(7laims.

My invention relates to' electric incandescent lamps and similar devices comprising an electric energy translation element, such as a filament, enclosed or sealed in a bulb or envelope, and to methods of manufacturing such devices. More particularly, my invention relates to improvements in the type of devices shown in United States Patent 1,988,290, D. K. Wright, and my United States patent application Serial No.

669,189, Filed May 3, 1933, Patent No. 2,084,192,

' in which the internal mount," comprising the translation element or filament and its supporting structure, is mounted on the base independently of the attachment of the bulb to the base.

by fusion so that the base becomes an integral part of the lamp or similar device. Such a construction has the advantages that the current lead wires do not pass through the. glass eneliminated, it is much easier to locate the translation element accurately and uniformly with reference to the base, the internal mount structure is greatly simplified, lamps may be made with 25 very .short light center length, the number of operations is reduced considerably, and the device is much simpler and stronger and less expensive to make. Various features and advantages of my invention will appear from the following description of species thereof and from the drawings.

In the drawings; Figs. 1-4 show various steps in the manufacture of an incandescent lamp according to my invention, Fig. 4 showing an elevation, partly in section, of the completed lamp; Fig. 5 is a perspective viewof the base; Figs. 6 and 7 are elevations, partly in section and wholly in' section respectively, of the base end of the lamp illustrating alternative methods of sealing an exhaust opening in the base; Fig. 8 is an elevation, partly in section, of a lamp having a modified mount structure; and Fig. 9 is an elevation, in section, of a modified base having three contacts for a multiple filament lamp.

Refering to Fig. l', the base illustrated therein is of the screw-thread type comprising a cylindrical metal shell i0 and a metal eyelet Ii. The shell it has a round cavity or depression i2 in the bottomor end thereof with a round opening ii at the center thereof and a narrow tongue or tab ll extending axially inward of the shell from the rim of said opening, the said tongue it being formed from the material punched out to form the said opening. The eyelet ii is substantially 55 cylindrical or conical and has an outwardly ex- The glass bulb wall is sealed directly to the base velope, the usual separate basing operation is tending flange I! at one end, the opposite end being inwardly recessed at l6 and having an opening I! therein through which the lamp subsequently exhausted.

The base may be assembled as shown in Fig. 5

' 1, with the shell it held in an inverted position in a suitable holder with the flanged portion ,of a fiare I 8 of glass or other vitreous material disposed in the cavity i2. The eyelet ii is gripped in a holder such as a suction head or mechanical jaws and is brought down against the upper end of the glass flare l8. Heat is then applied, preferably by directing the flame of a ring type burner downwardly into and around the edges of the cavity i2 to heat the metal parts and to fuse the glass flare it. During the fusion of the said glass flare ii, the eyelet ii is'pushed downward by the weight of the head in which it is held until a stop on said head engages a coacting stationary stop, thereby spacing the eyelet Ii and shell III as shown in Fig. 2 and uniting the two parts through the medium of the fused glass seal i9. As shown in Fig. 1, preferably prior to the assembly of the shell l0 and eyelet I i, the ends of lead and support wires 20 and 2| are secured, as by welding or clamping, to the tongue M on the shell ill and to the eyelet II respectively. The shell in and eyelet ii may, if desired, be assembled in an upright position, the shell being pressed downward during the fusion of the glass ring it After the base has been assembled, a filament 22, which may be of the coiled or coiled-coil type, is mounted on the ends of the lead wires 2li-2i. The said filament may be mounted directly on the ends of the said leads. However, as shown in Fig. 2, a separate filament assembly may be made comprising a pair of bent wires 23 and 24 having their ends embedded in a glass bead 25 to form a U'-shaped frame, the filament 22 being secured to the ends of said wires. The filament may be supported at its middle by the looped end of a support wire 26 having its opposite end embedded in the glass bead 25. The filament assembly is then mountedmerely by securing, preferably by welding, portions of the wires 2324 to the upper ends of the leads -20 2|. Obviously, by using a suitable Jig the filament may be positioned very accurately with respect :to the base.

The next operation is the sealing of a bulb or envelope to the base. Referring to Fig. 3, the base and mount assembly may be placed in an upright position on a suitable holder 21, and a bulb 28, held in a suction head 29, may then be lowered so that the neck 30 thereof enters the inside of the base shell l0 and is seated firmly on the bottom thereof. The bulb may however, if deslred,- -be. pushed upward into the inverted base held in the position'shown in Fig. 2 so that the base need not be removed from its holder. The holder 21 has a cavity 3! at thecenter thereof shaped to engage the eyelet Ii and an annular groove 32 which forms a ring 33 which engages the bottom of the shell l0 around the cavity l2 and prevents the base from wobbling. The groove 32 also prevents excessive heating of the fused Joint between the shell I0 and eyelet ll during the sealing of the bulb to the base. The base shell I0 and the adjacent neck 30 of the bulb are then heated, preferably by a ring type burner 34 surrounding said shell,- to cause said bulb neck to become plastic, and air under pressure is admitted to the interior of the bulb through the opening I! in the eyelet l I and through the cavity 3| and a passage 35in the holder 21 so that the plastic glass is I pressed against the inner surface of the base shell l 0 to form a tight seal.

The final step is; the exhausting and tipping off."- One methodof accomplishing this is to seal an end of a glass exhaust tube 36 (Fig. 4) to the surface of the recess 16 in the end of the eyelet l I. The lamp is then exhausted in the usual manner, and fllled withgasif desired, through the opening I! in the eyelet' ll, after which the exhaust cured, preferably by welding, to the'leads. ll and II respectively." A heat deflecting-shield li' of a metal such as aluminum, or an" insulating ma-,

terial such, as mica, may be mounted onvthe tube 39 if necessary to prevent overheating of the base when the lamp is burned in a base-up position. The bulb 28 is sealed tothe base shell ll and the lamp is exhausted, and filled with gas when desired, as explained above with reference to Figs. 3-6.

Fig. 9 shows a multipleiilament lamp having let H, which is united by a fused seal-ll'to thecavity or depression 43 in a metal disc 50 of the same shape as the bottom or end of the shell II. The said disc 50 is in turn united by a glassseal 5|, formed by the fusion of a glass ring, to a screw-threaded metal shell152-1 One end 'oi -each of the lead wires 53, 54 and 55-is secured, preferably by welding, to the eyelet: ll, disc ill and shell 52 respectively. One. fllament fl'may be mounted on the ends of the-leads 53 -and and another filament 51 on the ends of the leads 54'- and 55, the lead 55 in this: case thereby servingas a common lead for both filaments. The bulb 58 is sealed to the base shell52in the same man-I ner as shown and explained with reference to" Fig. 3. The lamp is then: exhausted, and gas fllled if desired, through theeopening il in thetube 36 is heated. to" close and sever it and tha eyelet ll and then sealed at'ill as-shownandexresidue is fused down to form a glass seal 31 which seals the-opening H. The glass seal 31 is sheltered within therecess 16 thereby eliminating any sharp projections and preventing accidental breakagevof'the said seal.

Alternative methods oi exhausting and sealing the exhaust-"opening are illustrated in Figs. 6 and '7, the lamp in each case being exhausted, and fllled with gas if desired, within a chamber. In Fig. 6, the lamp is disposed in a base-up position and pebbles 38 of a fusible material such as glass, preferably a low?- melting point glass such as French sealing glass made by the Corning Glass Works, are placed inthe recess IS in the end of the eyelet ll. After the lamp has been exhausted, heat is applied: tothe end of the eyelet II to fuse the glass pebbles 38 to form a seal like that shown at 31 in Fig. 4. In Fig. 7, the lamp'is placed in a neck-down position and the glass pebbles are pIacedE'within the eyelet ii, the said pebbles beingfused after the lamp has been evacuated. Instead of glass pebbles 33, a small piece or pieces--of-a,-Iusible metal may be used to seal the opening. l'l.-

In the modification shown in .Flg. 8, a long flared glass tube 39= -is-used in place of the short flare i8 ofv Fig.1, and it is assembledsothat it extends into the bulb. The seal is is fused from the flare or flangetatthe end of the said tube 39, although if desired-,- an extra glass ring or flare similar to the flarellmaybe. used to provide more glass for theseal l3. One lead wire 40 is secured-at'one end.to-the tongue I! on the base shell ID. The other, lead may comprise two sections ll and42,1the-.section "constituting a fuse wirewhich within the tube 39 which serves as a shield? therefor. The said tube 39 may be open at its-upper end, or it may beclosed and sealed around -th'e lead wire as shown in the drawings-inwhichcase an opening l3 is'made in the sideofthe said tube in order that the bulb may be evacuated; The coiled or coiled-coil fllam'ent 22 is shown i'n this case as extending along the longitudinal axisof. the bulb 28 and is mounted on support wires? and 45 which are acplained with reference to Figs. 4-7.

Where the glass partsv of. the devices described: above are made of soft glass, themeta'lparts of the base are preferably made. of an iron alloy containing about twenty-eight. per cent 01' chromium. Such an alloy is one marked by the Allegheny Steel Corporation as Allegheny 55." Where the glass parts are-made of a hard glass, such as "Pyrex", the metal may be an iron-nickelcobalt alloy such as that known as Fernico" and disclosed in the United States Patent 1,942,260,

ing bayonet pins or other engagement meanssuch as a flange thereon.. The shape of the eyelet ll may be varied-for example, a plain disc may be used. The metal-to-glass seals may be made by heating the metal by means of a high frequency coil instead of a gas flame. A heat deflecting disc may also be used in the lamp shown in Fig. 4, similar to the disc 48 in Fig. 8 and supported by the leads 2li-2l. The filament constructions could also be changed to accommodate various demands.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. The method of manufacturing an electric lamp or similar device which comprises assembling a metal base shell and eyelet with a'glass ring therebetween, said shell and eyelet each having one end of a lead wire secured thereto. applying heat to fuse said glass ring and unite said shell and eyelet, mounting a filament on the opposite ends of said lead wires, inserting the neck of a bulb into said shell, applying heat to said shell to fuse the portion of the said bulb neck located therein and cause. it to be sealed to-the inner surface of said shell, exhausting the interior of said bulb through an opening in said eyelet and then sealing said opening with a fusible material.

2. The method of manufacturing an electric lamp or similar device which comprises assembling a metal base shell andeyelet with a glass ring therebetween, said shell and eyelet each having one end of a lead wire secured thereto, applying heat to fuse said glass ring and unite said shell and eyelet, securing to the opposite ends of said lead wires a pair of support wires united in insulated and spaced relationship and carrying a filament, inserting the neck of a bulb into said shell, applying heat to said shell to fuse the portion of the said bulb neck located therein and cause it to be sealed to the inner surface of said shell, exhausting the interior of said bulb through an opening in said eyelet and then sealing said opening with a fusible material.

3. An electrical device comprising a glass bulb having a neck portion, a cylindrical metal base shell sealed directly to said bulb neck, said shell having an inwardly flanged bottom with a round depression therein, a substantially cylindrical eyelet at the bottom of said shell having an outwardly extending flange united by a fused vitreous seal to the said depression in the bottom of said base shell, said eyelet having a sealed exhaust opening therein, a pair of lead wires in said bulb,

one end of each of said lead wires being secured respectively to said shell and said eyelet, and a filament in said bulb mounted on the opposite ends of said lead wires.

4. An electrical device comprising a glass bulb having a neck portion, a cylindrical metal base shell sealed directly to said bulb neck, a glass tube, a metal eyelet on the end of said base shell united to said shell through the medium of a fused glass seal formed from a portion of said glass tube, said glass tube extending axially into said bulb, a lead wire secured at one end to said base shell and extending into said bulb, another lead wire secured at one end to said eyelet and extending through said glass tube into said bulb, the portion of said second-mentioned lead wire located within said tube constituting a fuse wire, and a filament mounted on the ends of said lead wires within said bulb, said eyelet having an exhaust opening therein communicating through said glass tube with the interior of said bulb, said zexrlzzlust opening being sealed with a fusible ma- 6. An electrical device comprising a glass bulb having a neck portion, a cylindrical metal base shell sealed directly to said bulb neck, a glass tube, a metal eyelet on the end of said base shell united to said shell through the medium of a fused glass seal formed from a portion of said glass tube, said glass tube extending axially into said bulb, a lead wire secured at one end to said base shell and extending into said bulb, another lead wire secured at one end to said eyelet and extending through said glass tube into said bulb, the end of said glass tube opposite said base being fused around a portion of said lead wire, the portion'oi' said second-mentioned lead wire located within said tube constituting a fuse wire, and a filament mounted on the ends of said lead 'wlres within said bulb, said eyelet having an exhaust opening therein communicating through said glass tube and through an opening therein with the interior of said bulb, said exhaust opening being sealed with a fusible material.

6. A base for an electric lamp or similar device comprising a shell of metal readily sealable to glass having an inwardly flanged bottom with a round depression therein, and a substantially cylindrical metal eyelet at the bottom of said shell having an outwardly extending flange at one end united by a fused vitreous seal to the said depression in the bottom of said shell, said eyelet having an exhaust opening therein.

'7. A base for an electric lamp or similar device comprising a shell of metal readily sealable to glass having an inwardly flanged bottom with a round depression therein, and a substantially cylindrical metal eyelet at the bottom of said shell having an outwardly extending flange at one end united by a fused vitreous seal to the said depression in the bottom of said shell. the opposite end of said eyelet being inwardly recessed and having an exhaust opening therein, said recess serving as a shelter for a fused glass seal.

8. An electrical device comprising a 'glass bulb having'a neck portion, a base comprising a cylindrical metal shell sealed directlyto said bulb neck, a metal disc sealed to the bottom of said shell through the medium of a fused glass ring, and a metal eyelet sealed to the bottom of said disc through the medium of a fused glass ring, a plurality of lead wires each secured at one end to said shell, ring and eyelet respectively and extending into said bulb and a plurality of filaments mounted on the opposite ends of said lead wires, said eyelet having an exhaust openi 8 therein sealed with a fusible material.

PAUL O. CARTUN. 

